Try "College Camp, Wisconsin". It was a "summer post office" established back in 1915 and closed in 1954. It was a sub-section of Williams Bay, Wisconsin and ultimately all mail was re-directed to that post office during the off-season.
The date of your postmark appears to be 1925, in which case for that year, the "summer post office" use was from June 8 to September 8, 1925, which fits the date on your postmark.
A further piece of information connects it as the cover is from the YMCA and according to Wiki:
Quote:
George Williams (YMCA), the founder of the YMCA whose officials and students of Chicago-based George Williams College frequently met just west of the town of Williams Bay and later established a camp in the village on the shores of Lake Geneva. George Williams College folded in the 1970s and is today part of Aurora University, which today maintains the campus.
Posted 11/23/2012 9:53 pm
